During questioning by a government inquiry, Packer blamed his "medical state" for the threats which he agreed were "shameful" and "disgraceful". Packer, who confirmed on Tuesday that he has bipolar disorder after revealing previously he had mental health problems, said he should have told shareholders about his personal issues instead of keeping them secret.
"I think my medical state is what it reflected most on," Packer said of the emails to the person. Packer, who quit the Crown board weeks later without disclosing medical issues, no longer works at the company but retains 37% of Crown, a stake worth A$2.2 billion ($1.57 billion).
One of Australia's wealthiest people, Packer shuns public attention beyond staged photo opportunities or prepared statements. Packer testified via videolink in a jacket and tie from an undisclosed location, reported by Australian media to be on board a yacht in the South Pacific.
The government inquiry comes as the New South Wales state casino regulator considers whether Crown should be allowed to proceed with plans to run a 75-floor, A$2.2 billion ($1.6 billion) casino tower in Sydney, just months before its scheduled opening.
The risk of the company losing its licence grew last year following media reports, denied by the company, that Crown hired tour operators linked to organised crime to bring wealthy foreign gamblers, largely from China.
Packer denied knowing that Crown staff set up informal offices in residential locations in Guangzhou, China, where advertising gambling is illegal, to avoid detection. In 2016, 16 Crown staff were jailed in China for violating anti-gambling laws. [D-REUTERSNEWS-T004/Ie4b85a305a2b11e79b7692983d739d5a]
"I believe that Crown had legal advice that said what they were doing was legal," Packer said. "It's a failure in compliance. A significant failure."
Asked if he accepted that his actions in sending the emails to the unnamed person amounted to shameful conduct by a company director, Packer said, "I do". Asked if his actions were "disgraceful", he said, "Yes".
The regulator should nonetheless accept Packer as a person of integrity "because I'm being treated now for my bipolar (condition), because I was sick at the time", he said.
Packer continues testifying on Wednesday.
($1 = 1.3980 Australian dollars)
(Reporting by Byron Kaye; Editing by Kenneth Maxwell)
By Byron Kaye
